Clutches of the above type are well-known and are commonly referred to as synchronizers or synchronizer clutches. Many synchronizer clutches include a friction clutch (es) to synchronize the jaw clutch members, blockers to prevent contact or engagement of the jaw clutch members prior to synchronization, and springs or (as herein) spring pins. The spring pins effect engagement of the blockers by initially moving the friction clutch into engagement with relatively low force in response to incipient engaging movement of one of the jaw clutch members. One species of such synchronizer clutches are the double acting synchronizer clutches disclosed in U.S. Pat. Nos. 2,667,955 and 4,125,179 to L. A. Bixby and P. R. Cochran, et al., respectively. The Bixby patent discloses spring pins which each consist of a pair of rigid semicylindrical members biased apart by a spring disposed in a cavity defined by the rigid members. The spring pins of Bixby are believed to be rather expensive to the spring pins disclosed herein. The Cochran patent discloses compressible C-shaped spring pins. The springs pins of Cochran are believed to be substantially less expensive to produce than the spring pins of Bixby. However, the spring pins of Cochran are also believed to be subjected to rather high stresses when the pins compress, i.e., when the pins flex radially inward.